The long-term objective of this research project is to develop a multi-spectral single-scan lung imaging system. Our primary hypothesis is that the essentially simultaneous and co-registered acquisition of multi-spectral projection data for each path (line-integral) through the patient will help in the detection and characterization of lung diseases. At the heart of the project will be the development of a fast and low-noise full-frame sampling narrow-aperture CMOS detector that can be scanned behind the body of interest. In synchronicity with each detector-row advance and full frame sampling, the x-ray spectra are varied (via techniques, filtration, and potentially x-ray anode track and target material selection) in such a way that each line-integral through the body to be imaged and analyzed is sampled at a multiplicity of spectra. As a result, in a single scan of the anatomy a multiplicity of essentially co-temporal and co-registered projection images are acquired under separate spectral conditions. These image data are then decomposed onto a multiplicity of basis functions (which may then be displayed separately or in various weighted combinations). In Phase I of this application we will focus on the proof of feasibility for co-temporal and co-registered multi-spectral chest imaging. The Specific Aims for Phase I research are to: (1) Substantiate the approach potential for lung cancer screening; (2) Demonstrate system feasibility. [unreadable] [unreadable]